Variable speed tension impact machine



Dec. 3, 1935. R. K. HASKELL ET AL 2,022,566

VARIABLE SPEED TENSION IMPACT MACHINE Filed Oct. 2, 1935 2 Shets-Sheet 1V Invanturs Rmh rt Kfiaskell Hamld13-Mann EY WW 1366- 1935. R. K.HASKELL Er AL VARIABLE SPEED TENSION IMPACT MACHINE 2 Sheets-Sheet 2Filed 001:. 2, 1955 Inventurs Rnbart. Kl-Iaskell Harald [3-MannAttnrne'y Patented Dec. 3, 1935 PATENT oFFICE VARIABLE SPEED TENSIONIMPACT MACHINE Robert K. Haskell, United States Army, and Harold 0.Mann, both of Watertown, Mass.

Application October 2, 1933, Serial No. 691,826

3 Claims.

(Granted under the act of March amended April 30, 1928; 370 0. G. 757)The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to us ofany royalty thereon.

The subject of this invention is a variable speed tension impact machinefor testing material to the breaking point by tension impact.

The main objects of the invention are the provision of a device in whichthe speed of the impact member at the time of impact may bepredetermined; and the provision of means for measuring the energyabsorbed by the test specimen on impact.

To these and other ends, the invention consists in the construction,arrangement and combination of elements described hereinafter andpointed out in the claims forming a part of this specification.

Practical embodiments of the invention are shown in the accompanyingdrawings wherein:

Fig. 1 is a view in elevation, partly in section, of a machineconstructed in accordance with the invention.

Fig. 2 is a sectional view taken on the line 22 of Fi 1.

Fig. 3 is an end elevation.

Fig. 4 is a schematic .view in elevation of a .modified form of themachine.

Fig. 5 is a fragmentary detail in elevation of the pendulum. I

Fig. 6 is a sectional view on the line 6-6 of Fig. 5.

Fig. 7 is a view in elevation partly" in section of another modifiedform of the machine.

Fig. 8 is a fragmentary detail in elevation of the pendulum.

Fig. 9 is a sectional view on the line 99 of Fig. 8.

Referring to the drawings by numerals of reference:

There is provided a suitable supporting frame I in which a shaft 2 isjournaled' carrying preferably fast thereon, a rotatable element 3herein shown as a disk formed with segmental peripheral flanges 4.Rotation may be imparted to the element 3 through any desired means asfor instance a motor 5.

Pivotally mounted on the rotatable element and occupying thediametrically opposite spaces between the ends of the flanges 4 are animpact member 6 and a counter weight I respectively. To permitretraction of the counterweight and impact member,'a disk 8 is looselymounted on the shaft 2 and is connected through links 9 and I with theimpact member and counterweight respectively. Means are provided forholding the impact member and counterweight in retracted position hereinshownas a latch ll carried by the element 3 and adapted to engage anotch l2 in the disk when the disk has been ro- 5 tated to position toretract the impact member and counterweight. The latch may be releasedby the operator in any desired manner when the element 3 has attainedthe proper speed, the method herein illustrated consisting of a camsurface l3 movable as by the lever 13a on the support to position tocontact the stud M on the latch and release the latch.

The impact member when in extended position rests against a face of theflange 4 so as to be 15 supported firmly when delivering a blow and thecounterweight is likewise supported, when extended by a face of theflange to prevent movement of the parts beyond a fixed position.

Mounted in the support for oscillation out 20 a shaft I5 is a penduluml6 formed with-anoffset portion adjacent to the rotatable elementatoprovide a downwardly facing shoulder ll drilled and tapped to receive anend of a test specimen l8 to the other end of, which is secured a tup 25I9 extending laterallyof the pendulum in position to be struck by-theimpact member when in extended position.

Mounted on the shaft I5 adjacent to the pendulum is a pointer 20 whichis rotatable on the shaft and has sufficient frictional contacttherewith to remain stationary at any position to which it may be moveduntil a force other than the action of gravity upon the pointer isapplied to move it. A pin 2| projecting from the pendulum contacts thepointer when the pointer is at zero setting and the pendulum is at rest.A scale 22 is supported in position to register with the pointer. Inorder that the tup and test specimen may be recovered easily after thespecimen is broken, a base 23 maybe provided and partially filled withsandijior like material for receiving the tup and portion of the testspecimen upon reception of the latter.

The operation of the device is as follows:

A test specimen is threaded into the pendulum and the tup. With theimpact member and dulum. The greatest oscillation of the pendulum isindicated by the pointer which is carried up the scale by the pendulum,but because of its frictional contact with the shaft, does not returnfrom such position. In order that the pendulum may not swing back andinjure the box 23, a brake, not shown, may be applied to check thereturn swing. f

The modified form shown in Fig. 4, is the same as that heretoforedescribed with the exception that the position of the pendulum has beenchanged necessitating a slight-modification in the form of the pendulum.

In this instance the shaft I5 is so placed that the lower end of thependulum is adjacent to the rotatable element 3 and such end isbifurcated as at 24 to permit the passage of the periphery of theelement 3. Within the bifurcated portion is the rib 25 which is drilledand tapped to receive the end of a test specimen to the other end ofwhich is secured the tup as heretofore described.

In the modified form shown in Figs. '7, 8 and 9 the rotatable element 3and pendulum are mounted on the same shaft. In this instance thependulum 26 is bifurcated to straddle the element 3 and a rib 21 isformed at its lower connected end which rib is drilled and tapped toreceive the test specimen as heretofore described.

We claim. 1. A variable speed tension impact machine embodying, arotatable element, retractable impact members carried by said element,retractable counterweights carried by said element, a connection betwenthe impact members and the counterweights operable to retract the same,releasable means for holding the members and 5 counterweights retracted,means for releasing said holding means when a predetermined speed hasbeen attained by the element, and means for registering the energyabsorbed on impact.

2. A variable speed tension impact machine 10 embodying a rotatableelement, retractable impact members carried by said element, a platerotatable with the element and rotatable with respect thereto, aconnection between the plate and the impact member for retracting thesame, means for locking the plate to the element to hold the impactmembers retracted, means for releasing the locking means, a pendulumadjacent to' the rotatableelement, means for securing a specimen to beruptured to the pendulum, and means for indicating the force of impactthrough the swing of the pendulum. v

3. A variable speed impact machine embodying a rotatable element,retractable impact members carried by said element, releasable means forholding the members retracted, a pendulum adjacent to the rotatableelement, means for securing a speciman to be ruptured to the pendulum,and means for indicating the force of impact through the swing of thependulum.

ROBERT K. HASKELL. nanom c. MANN.

